Given that progressively there are more and more machines and apparatus that operate automatically by means of inserting coins, there is a large number of devices and systems used to recognize inserted coins in order to prevent acceptance of counterfeit ones.
Hence, the selection or validation of coins is done by means of a selector that is assembled in relation to the coin slot. It may have other elements such as coin deposits and coin returns, in such a way that the validation of the coins is as reliable as possible, but it also happens that the way to make "counterfeit coins" is inexpensive and more and more sophisticated and therefore, validating systems must be continuously improved in order to fight against the new forms of counterfeiting.
Among the existing mechanisms for selecting and validating coins, we can cite Patent of Invention P8602773, Utility Models 283634, 291035 and 291036, as well as Patent of Invention P9002145 and its Certificate of Addition P9200624, wherein different coin selecting mechanisms are presented and described.
Patent of Invention P8602773 claims an "electronic coin selector", which is useful in those automatic vending machines, which are coin-operated, in such a way that the same is provided with a solenoid without a ferromagnetic core, creating the magnetic field in vacuo and through whose core the coins to be validated pass, disturbing the built-in oscillator, said disturbance being detected by computer means and these disturbances being different in each coin, which collaborates with the sensor to determine the alloy, being able to cover a larger number of coins selected according to their alloy.
Utility Model no. 283634 claims an "improved electronic coin selector", useful in machines and apparatus that are coin operated, which in the selection of the inserted coins carries out the comparison of the data obtained with the previously stored information, for which purpose in the path along which the coins follow in the selector, they face three sensors each one of which determines the section, diameter and alloy of the coins, these three readings being processed by a microcomputer determining the type of coin being dealt with, in such a way that if the obtained information coincides with any of the stored information the coin is accepted and on the contrary it is rejected.
Likewise, Utility Model no. 291035 claims an "electronic coin selector", which includes a sensor by which the coins pass for their verification, measuring the diameter in order to continue to pass between a hollow coil, which based on the previously measured parameter will verify the volume and alloy of the cited coin, achieving with its use greater stability in temperature variations.
Utility Model no. 291036 claims an "electronic coin selector", by means of which the coins in their passing through the inside of the selector, for their verification, pass through a hollow coil placed between two sensors that measure the section and diameter, in such a way that said hollow coil that generally has a rectangular prismatic shape, verifies the alloy and volume on the basis of the previously measured section thus achieving total reliability.
Patent of Invention P9002145 claims a "device to obtain the mechanical characteristics of coins", which includes an elastically deformable element (gage) by the effect of the weight of the coins during the passing thereof over said element, depending the formation on the weight of the coins and on the position thereof over the same, in such a way that said elastically deformable element is sensorized for the purpose of obtaining an electric signal inherent to the characteristic of the coins.
Certificate of Addition P9200624 of the above mentioned main Patent P9002145, claims some "improvements of the elastically deformable element", which remains inserted by one of its ends and has a side widening in one of its end portions, that is tightly inserted in an embedding formed in the selector, said embedding remaining retained externally by an anvil that is fixed to the selector and presses a strip towards its embedding the same moving in a cantilevered off manner.